Device foeunscrewing and withdrawing pipe



H. W. FLETCHER.

nEvlcE EUR uNscHEwlNG AND WITHDRAWING PIPE.

APPLICATION FILED MAY 29, |919. I

Patented Deo. 9, 1919.

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HAROLD W. FLETCHER; or HOUSTON, TEXAS.

DEVICE FOR UNSCREWING ANI)` WITHDRAWING PIPE.

Specification ,of Letters Patent.

Patented Dec. 9, 1919..

Application filed May 29, 1919. Serial No. 300,551.

My invention relates to an improvement in devices for unscrewing and withdrawing pipe or casing from wells, mines, etc., or for other similar uses.

The pipe ordinarily used in oil or water wells, mine-s, etc., is almost invariably threaded for connection with the coupling with a right hand thread; that is, the thread which is engaged by a rotation of the pipe in a righthand direction and is disengaged by a rotation of the same in a lofthand or counter-clockwise direction. WhenV it is desired to unscrew pipe and withdraw it from the well, it is necessary to reversethe direction of .rotationV at the head of the well so as to give the desired lefthand movement to the pipe. Usually the oil or water wells are of substantial depth, and if it is desired to withdraw a broken off length of drill stem from the well, aitap is lowered down inside the well for a certain depth and, when the saine is attached to the pipe so as to obtain a grip thereon, the tool is rotated in a left hand or counter-clockwise direction to unscrew Vthe section of pipe `in order that it may be withdrawn. Where the pipe or casing has become sanded up or stuck in the well so that it becomes iinpossible to withdraw the whole string of pipe at one operation, this device is especially useful. As the tap is attached to the end of a piece of the drill stem, `it is neccss-ary that the lengths of pipe which make up this piece of drill stein should bethreadf` ed in a left hand direction in Aorder to pre'-4 vent the drill stein from itself unscrewing and being left in the well. This necessitates keeping on hand a large amount of pipe with a left hand threadthereon for use in this particular operation.

An object of my invention is to provide a tool which may be attached at the end of a drill stein, threaded in the ordinary right hand direction, andwhich will serve to give the desired left hand .motion to the pipe which it is desired to nnscrew and withdraw.

Another object is to provide a. tool of the character described which shall be simple and rugged in construction, and which will beof such compact nature that it may operate in the constricted space within the bore hole of the well.

Other objects and advantages of my invention will more clearly appear in the description which follows, and will be set forth with more particnlarity inthe claims.

Referring nowto the drawings forming a part of-tliis specification, and in which lijke numerals are applied to like parts throughout the several views, Figure 1 is a centr-al longitudinal section through my device,rthe central shaft thereof being shown in elevation; Fig. 2 is a transverse section thereof taken on the plane 2*#2 ofFig. 1; Fig. 3 is a transverse section taken on the plane 3-3 of Fig. 1; `Fig. -i is a similar section on the plane 1w-t of Fig. 1.

' My invention as disclosed in the drawings herewith includes a. centralshaft 10, having an upper cylindrical head 1l, and threaded at 12 for attachment to an ordinary right hand drill stem. The shaft 10 is concentric with the axis of the drill stem for a short distance7 and is provided with an eccentric downward extension 13, which is reduced slightly in diameter toward the lower onehalf thereof to furnish support for a. thrust bearing 32 during the rotation of thev shaft. `This reduced portion 1i is threaded'midway of its length at 21 to accommodate a nut to support the bearing 32, and is still further reduced at the lower end at l5, where it furnishes attachment `for a radial bearing ring 29.

The section 10 of the shaft is provided with an outer bearing sleeve 16, which is threaded at its lower end, and to another sleeve 17, of shorter length, said sleeve 17 having inwardly projecting gear teeth 18 on the interior face thereof. Mounted upon the eccentric portion 13 is a gear 19, which is, of small diameter toward the upper end, and toothed eXteriorly at 20 to mesh on one side of the said gear with teeth 18 on the sleeve 17. The lower end of the gear sleeve 19 is enlarged in dian'ieter to form a larger gear 25 provided with outwardly extending teeth 26. The said teeth 26 are adapted to mesh on one side only with another annular gear 23 of larger diameter than. the gear sleeve 17, and which is also provided with inwardly extending teeth 2i.

Between the two outer gear sleeves 17 and 23, I have provided a hearing ring 27 which fits within a recess in the adjacent ends of these two gear sleeves and has an outwardly extending hearingportion 28. seen from Fig. 1, this ring serves as a bearing to take up wear between the rotating parts and will fit closely between the two gear sleeves, so as to prevent the entrance of grit or sand from the outside of the tool to the inner rotating parts. This hearing may he removed and replaced when worn. j

The sleeve 23 having thereon the gear teeth 21 toward its upper end, is extended downwardly for attachment to another lower sleeve, 30, to which `it is threaded. This downward extension has an inwardly projecting flange 31, forming a shoulder beneath the gear box formed within the gear sleeve 253, and vinterlitting with the thrust hearing in the manner shown in Fig. 1. The lower end of sleeve is threaded, as previously described, for attachment to the sleeve 30. The inner upper part of the sleeve 50, for distance equal to the length which is threaded into the sleeve 23, forms a chamber within which the nut 22, attached to the shaft 1a in the manner described, is rotatable. The nut may he tightened into place upon the shaft as shown at 21, so as to form a lower retaining means for the hearing member said hearing member resting partly upon the nut and partly upon the upper shoulder of the sleeve 30. n Cotter pin 33 is placed through a hole in the shaft directly oelow the nut 22 furnishing a locking means to prevent the unscrewing of said nut. y

The hearing member on the lower end 15 of the eccentric portion 13 of the shaft 10, is fitted within the sleeve 30 so as to bea-nat all times aga-inst the inner surface thereof. As the portion 15 of the shaft is eccentric and the sleeve 3G is bored eoncentrieally with the shaft 10, the bearing member 29 is set eccentrically upon the portion 15 of the shaft in such a manner that when the shaft rotates with gyratory motion within the sleeve 80, the hearing 29 will rotate evenly in constant contact with the inner portion of the sleeve 30. The bearing member 29 is retained upon the portion 15 of the shaft by means of a pin 8i which is adapted to pass directly through the said bearing member and the shaft, and is retained in position by contact of the pin with the inner walls of the sleeve 80. The bearing member 32 previously described is fixed upon the ortion let of the shaft hy means of a slidah e ley 35. This bearing member will he seen to be also eccentric, as compared with the sleeve 23, within which it rotates, to accommodate the As will he gyratory motion of the shaft at thatY point in the manner previously described in relation to the bearing member 29.

The sleeve 30 is extended downwardly helow the end 15 of the shaftiO for a short distance as illustrated in F ig. 1, and is threaded into the upper end of a coupling sleeve 86.. The lower end of the sleeve 36 is extended inwardly to forni a flange 37, adapted to fit closely about the slidahle upper end 38, of a drilling jar 39. The por tion 38 of the said jar is polygonal in shape and has an upper outwardlyextending flange -10 adapted to prevent the jar from being disconnected from the sleeve 35 in an obvious manner.v lThe drilling jar 39 is attached at its lower end to a tap l1 adapted to grip the pipe which is to be unscrewed. Where longitudinal play of the pipe is otherwise provided for, no jar is necessary. l also desire to use my device in unscrewing rods or shafts lodged inthe well and do not wish to be confined to the Vuse of any particular form of tap or fishing tool. Any form of known connecting member is conteniplated.

VThe upper sleeve 16 of this tool must in operation he held stationary within the well. F or this purpose 1 have provided a clamping means composed of jaws L12, of which I have shown three, toothed on their outer surfaces at 43, in order to obtain a firm and immovable grip upon the outer easing or wall of the well. These jaws project outwardly through openings M in the sleeve 16 fitting approximately water-tight within the opening. The inner end ofv each of these jaws is extended laterally at to provide a stop to limit the outward movement thereof. lfVater is pumped down under high pressure through the central channel leading from the Vdrill stem through the shaft 10 to a point within the sleeve 1G.

Lateral ducts 117 lead from the lower end of this channel outwardly to the chamber l5 within the saidr sleeve. The pressure of' this water will be exerted against the inner ends of the jaws which will act as pistons forcing the teeth 113 into gripping' contact with the casing- 9. A small passage d6 leads from the channel 46 downwardly through the tool to the drill pipe loelow.V VV hen the pump is stopped this passage will allow the water to run ofi", releasing the head of water above. and thus the pressure onthe jaws. A

In the operation of my invention, the rotation of the drill stein attached to the upper threaded end 12 of the shaft 1G will rotate the said shaft in a clockwise or right hand direction. The hydraulic pressure upon the jaws a2 will maintain the upper sleeve 1S in stationary'position. The sleeve lbeing threaded to the sleeve 17, willhence maintain the gear teeth 1S, also stationary. As the portion 13 of the shaft 10 is eccentric `gear 19 will be carried around inside the outer toothed sleeve, once with each rotation of the shaft. As the shaft rotates in a clockwise direction it will be `obvious that the gear 19 will be rotated in a contrary direction, thereby setting up a left hand rotation. The lower enlarged part 25 of the gear 19 is of larger diameter than that of the upper part in order to mesh properly with the vear sleeve 28 which is of greater internal diameter than the ,gear sleeve 17. The contact of the teeth 26 of the gear 25 with the inner teeth 2% of the outer sleeve 28, at one point thereon as .shown in Fig. i will cause the outer sleeve 23 to rotate in the same direction as the gear 25, but as may be readily seen the speed of rotation of the sleeve 23 will'be less than the speed of rotation of the shaft.

The rotation of the sleeve 23 will be communicatedto the sleeves 30 and 36 and from them to the upper end 38 of the drilling jar 39. When the pipe to be unscrewed is rotated by the tap 41 attached to the lower end of the jar, it is obvious that the rotation will be in a left hand direction thereby unscrewing the pipe, vbut as my device is fixed against movement within the casing by means of the jaws 4:2, no vertical movement of the same is possible. When the tap is first screwed into the pipe to be removed,'it must move downwardly several inches in order to thread the tap into the pipe; when the tap is come to a seat and a joint of the pipe below unscrews, the unscrewing will cause the same to move upwardly for a few inches, suliicient to detach the upper length of pipe from the upper fixed end of the pipe below. These vertical movements of the tap will be accommodated by the sliding contact of the jar 39 with the lower sleeve 36. l/Vhen the pipe has been unscrewed, the jaws may be released from contact with the casing by merely shutting down the pump, and the tool, together with the unscrewed pipe, may be withdrawn from the well.

Having thus described my invention, the objects and advantages of which will be clear without further explanation. what I claim as new and desire to protectby Letters Patent is:

1. A device for unscrewing pipe comprising a rotatable shaft` an eccentric portion thereon, a gear on said eccentric portion, a stationary annular gear meshing therewith, an enlarged lower gear on said first inentioned gear, a rotatable annular gear meshing with said lower gear, and means connected with said rotatable annular gear for attachment to the work.

2. In a device for nnscrewing pipe, the combination of a bearing sleeve, clamping means therefor, a vertical drive shaft in said sleeve, a gear sleeve on said bearing sleeve, a gear on said shaft operated by said shaft and gear sleeve, a second gear sleeve operated by said gear, a rotated work engaging member and a slidable connection between said second gear sleeve and said rotated member.

3. A device for unscrewing pipe comprising a. rotatable shaft, an eccentric portion thereon, a spur gear on said eccentricportion, a stationary gear sleeve meshing with said spur gear, a gear Ofdifferent diameter connected to said spur gear and rotating therewith, a driven sleeve actuated by said second named gear and means to connect said driven sleeve with the work.

il. A device for unscrewing pipe comprising an internally toothed gear sleeve, a shaft rotatable therein, means to anchor said sleeve to the Side of the well, a spur gear mounted eccentrically on said shaft and meshing with said gear sleeve, a gear of larger diameter connected with said spur gear,.a second gear sleeve driven by said larger gear, and a pipe gripping means connected therewith.

A device for unscrewing pipe comprising a right hand rotatable shaft, a bearing therefor, means to retain said bearing statienary` an eccentrically mounted spur gear on said shaft, an internally toothed gear sleeve connected with said bearing and meshing on one side with said spur gear, a second gearintegral with said spur gear, an operated sleeve driven thereby in a left hand direction, and means to engage the work.

G. A device for unscrewing pipe comprising a rotatable drive shaft, an eccentrically mounted spur gear thereon, a stationary gear sleeve coperating with said shaft to rotate said spur gear in a direction contrary to that of the shaft, a second gear integral with said spur gear, an interiorly toothed gear sleeve operated thereby, and

means operated by said last named gear sleeve to engage the work.

7. ln a device for unscrewing pipe, a drive shaft, a stationary internally geared sleeve, a spur gear on said shaft 'rotating eccentrically in mesh with said gear sleeve, a larger gear on said spur gear, a rotatable internally toothed gear sleeve driven by said larger gear, and an adjustable attaching member on said rotatable gear sleeve foi connection with the work.

ln testimony whereof, l hereunto my signature this the 26 day of May, A. D., 1919.

HAROLD YV. FLETCHER. 

